[abecedarius]

> In traditional music notation notes an octave apart do not resemble each other.

This is what I'd emphasize. To sight read, the mapping from sign to note has to be so automatic it's unconscious. In standard notation this mapping looks different at every one of the middle four octaves, which nearly quadruples the size of the "multiplication table" you're installing in memory. Since your exposure in practice to the further ends of that range is less frequent, you're still slowed down by some notes even once the middle ones are automatic to you. (And there's probably some "cross talk" for a long time -- at least, that's how it felt to me.)

It's strange to me when people are like "eh, what's the big deal" about a UX failure that seems this big.

[bentcorner]

At least for me as a very casual musician, I instinctively know how to map all the notes on the staff and maybe 2/2.5 lines above/below. Most sheet music uses the octave above/below notation when necessary too, so it's not common (for me) to need more than that.

When I was younger and played more complex pieces, my teacher and I would sometimes write down notes that were way out there just to help things along.

Personally at first glance this notation is jarring to read, and I don't know if it would make sense investing in learning this when literally everything else I've seen and own is traditionally notated. Where I find challenge in music is not understanding notes quickly enough, it's my physical mechanics, memory, and expressiveness.

[reikonomusha]

I don't agree with this "multiplication table" idea. Octaves have the same physical distance between notes on the page in traditional notation, so they can be identified at a glance. People typically do not read octaves by deciphering the bottom note, deciphering the top note, and saying "ah, this is an octave".

[abhorrence]

And even if they did, the stems of the notes (excluding half and whole notes) traditionally are as long as the distance between octaves. One of the things that I think makes traditional notation more robust for experts is the redundancy of information.

It also helps that for many instruments there’s a mapping between the layout of the instrument and the notation! This is less true for brass and the violin family, though I think even with them there are probably some arguments to be made about the harmonic series, or the spacing of strings in fifths.